This is an activity about the Doppler effect. Learners begin by simulating the noise made by a passing siren. After learning that the change in pitch results from movement, they investigate the definition of frequency, calculate change in frequency,...(View More) and learn how this applies to light and the study of astronomy. This lesson requires a Doppler ball, also referred to as a buzzer ball.(View Less)

This activity demonstrates Lenz's Law, which states that an induced electromotive force generates a current that induces a counter magnetic field that opposes the magnetic field generating the current. In the demonstration, an empty aluminum can...(View More) floats on water in a tray, such as a Petri dish. Students spin a magnet just inside the can without touching the can. The can begins to spin. Understanding what happens can be explained in steps: first, the twirling magnet creates an alternating magnetic field. Students can use a nearby compass to observe that the magnetic field is really changing. Second, the changing magnetic field permeates most things around it, including the aluminum can itself. A changing magnetic field will cause an electric current to flow when there is a closed loop of an electrically conducting material. Even though the aluminum can is not magnetic, it is metal and will conduct electricity. So the twirling magnet causes an electrical current to flow in the aluminum can. This is called an "induced current." Third, all electric currents create magnetic fields. So, in essence, the induced electrical current running through the can creates its very own magnetic field, making the aluminum can magnetic. This is activity four of "Exploring Magnetism." The guide includes science background information, student worksheets, glossary and related resources.(View Less)

This is lesson to begin learners' thinking about magnetic influence. Learners will watch a classroom demonstration about the effect of magnets on iron filings and then complete a journal assignment to record their reactions and thoughts. This is the...(View More) first activity in the Mapping Magnetic Influence educators guide.(View Less)

This is a activity about how reaction wheels affect spacecraft orientation (attitude). Learners will observe Newton's Third Law (action-reaction) in the changes caused by a reaction wheel acting upon a spacecraft suspended from a support wire and in...(View More) the ensuing interfering forces from the wire support. The experiment includes an option for demonstration and for learner investigation. Notes about gyroscopes are included.(View Less)